I have just finished reading Drug War Heresies by Robert MacCoun and Peter Reuter. Their conclusion is that policy change is necessary, but not the change legalizers or drug warriors suggest might hope for. They believe zero-tolerance policies are both unrealistic and at least the way they are practiced today, prejudicial, unfair and cruel. They also believe the proponents of legalization are as much driven by ideology as their drug war opponents and have unrealistic expectations.
The majority of the book is marked by a reliance on facts. Each analysis is couched in terms that define the limits of its reliability or applicability for any particular purpose. They make the adage false that you can say anything with statistics. They attempt to let the facts speak for themselves without any underlying bias. If you are looking for an ideological solution, you will not find it here. This makes the book appear cautious, which it is. They certainly want to see change in the current regime, they are not willing to do anything more than nudge us in the right direction.
Though they are sure that a legalization regime would reduce the overall harm done by drugs, they are as sure that the moral temper of the nation is incapable of supporting such a regime. As well, the commercial history of alcohol and tobacco tell that these industries have effectively skirted the boundaries set for them, increasing publicity and probably prevalence of use of their respective products in the society.
The European experiments with drug control are examined. They have problems not entirely unlike ours, yet the lessons learned from their policies are difficult to map onto our society.
I heartily recommend the book for its scope and concentration. On the basis of this sort of work, the probability of fair progress seems possible.